Digits Live Show: How RapLeaf Mines Data Online

As part of its ongoing “What They Know” series, the Wall Street Journal took a close look at RapLeaf, an internet company that maintains a database of over billion e-mail addresses, which it matches with information from people’s online and offline activities—including voter and property records. Julia Angwin and Emily Steel talk about where RapLeaf gets its information, who it shares it with and whether users can opt out RapLeaf’s database.

Also, the WSJ’s Jeffrey Trachtenberg talks about about Barnes and Noble’s push to get kids to read e-books.